Investigation of the cytotoxic effects of Thymbra spicata polysaccharides on MCF-7 breast cancer cell proliferation and migration in vitro conditions

Purpose Thymbra spicata species is a widely used plant, especially in the eastern Mediterranean region, and is known to have many health benefits. However, the effects of its polysaccharides on tumor cells have not been searched. We aimed to evaluate the biological effects of Thymbra spicata polysaccharides in MCF-7 breast cancer cells. Methods MTT test was performed to determine the cytotoxicity levels of polysaccharides and doxorubicin in MCF-7 and L929 fibroblast cells. The expression levels of VEGF and GSK-3β were examined immunocytochemically. For the in vitro wound healing assay, the scratch wound model was created in the shape of plus (+), and the closure percentage was calculated. Results Thymbra spicata polysaccharides and doxorubicin had a cytotoxic effect on MCF-7 cells depending on the dose increase. The percentage of wound closure also decreased in correlation with the MTT results. In L929 cells, there was no significant difference in VEGF and GSK-3β immunoreactivity after polysaccharides and doxorubicin treatments, but a significant decrease in VEGF and GSK-3β expression was observed in MCF-7 cells. We demonstrated that polysaccharides exert toxic effects by suppressing VEGF and GSK-3β molecules. In addition, the polysaccharides inhibited cell proliferation and migration, so in vitro wound healing was delayed at high concentrations.